This invention is directed to a method of producing petroleum from a petroleum-bearing formation wherein there is injected into the formation a hot aqueous fluid that is generated by firing a hot aqueous fluid generator with a sulfur-containing fuel and which generator emits a flue gas that contains sulfur oxides.
In the production of a hot aqueous fluid for use in a thermal oil recovery process, water is injected into a hot aqueous fluid generator as feed water and the generator is fired with a fuel such as gas or oil to heat the water and normally vaporize at least a portion thereof and form steam. The heated aqueous fluid is then injected via an injection well into a producing formation and oil or petroleum is produced therefrom. In the burning of the fuel, a flue gas is produced which flue gas has sometimes been treated but oftentimes has been vented directly to the atmosphere. In the burning of a sulfur-containing fuel, the flue gas contains sulfur oxides which desirably should not be vented to the atmosphere.
In an article published in CHEMICAL WEEK, Sept. 2, 1970, entitled "Smokestack Oxides May Get Sea Water Scrubbing," there is described a process that uses seawater to scrub sulfur oxides from power plant smokestack gases. In U.S. Pat. No. 1,271,899 to Henry Howard et al, there is described a process wherein furnace gases are brought into contact in a scrubbing tower with a dilute solution of alkali which effectively removes the greater part of the sulfur dioxide and yields a harmless exit gas and a dilute solution of sodium sulfite. The sodium sulfite is causticized by lime to form insoluble calcium sulfite which is recovered. Thus, the sulfur dioxide is recovered as calcium sulfite.
In U.S. Pat. No. 3,844,349 to Earl S. Snavely, Jr. and Theodore A. Bertness, there is described a steam stimulation method of producing petroleum wherein steam is generated by firing a steam generator with a sulfur-containing fuel and wherein the resulting flue gas that contains sulfur oxides is treated to remove the sulfur oxides therefrom prior to venting the flue gas to the atmosphere. The flue gas is treated in an emission scrubber vessel with an alkaline water which reduces alkalinity of the water, making it more readily usable as feed water for the steam generator.
In U.S. Pat. No. 3,880,237 to Earl S. Snavely, Jr. and Theodore A. Bertness, there is described a method of producing petroleum from a petroleum-bearing formation wherein a water, having bicarbonate ions, is treated with sulfur dioxide to reduce the bicarbonate ion concentration, thereby greatly reducing the formation of scale upon the addition of caustic to the water. Thereafter, a caustic is added to the treated water and the caustic water is injected into a petroleum-bearing formation and petroleum is produced therefrom. In U.S. Pat. No. 3,918,521 to Earl S. Snavely, Jr. and Theodore A. Bertness, a continuation-in-part application of the before-mentioned U.S. Pat. No. 3,844,349, an oxidation inhibitor is added to the alkaline water passed through he emission scrubber vessel to inhibit the oxidation of calcium sulfite formed in the emission scrubber vessel to calcium sulfate.
In U.S. Pat. No. 3,618,667, there is described a technique for treating water that contains hydrogen sulfide and oxygen dissolved therein to retard the corrosion of metal contacted with the water. A transition metal is added to the water to catalyze the reaction of the hydrogen sulfide and oxygen and thereby remove the oxygen from the water.